矩形金属屏蔽壳中几种介质腔谐振频率的精确计算

本文采用本征函数匹配法分析了在矩表金属屏蔽壳中有多层介质基片填充，放置任意位置的圆柱，圆环及方形介质腔的谐振频率，计算了谐振频率随外壳尺寸，介质腔尺寸变化的几组曲线，经与实验数据及圆柱屏蔽壳情况值比较表明本文结果正确。     

介质谐振腔任意模式谐振频率的求解

本文用模式匹配法计算圆柱形对称和非对称介质谐振腔内任意谐振模式的谐振频率。文章对有关公式做了详细的推导和必要的简化,计算结果与实验和有关资料都很一致。     

垫片加载圆柱介质谐振器的谐振频率计算方法

本文利用开波导法对有垫片加载的圆柱型介质谐振器之谐振频率进行了计算,其计算结果与实验吻合，误差小于1％。此方法适宜于实际工程。     

介质谐振器特性的有限元计算

本文应用有限元方法分析和计算了置于空气和不均匀介质中的圆柱形介质谐振器的谐振频率,以及介质谐振器与微带线的耦合参量。计算结果与现有文献的计算结果和实验结果相当吻合。     

有孔圆柱介质谐振频率的自动测试方法

从求解Maxwell方程本征值出发,采用MATLAB中PDE工具箱,借助可二维作图的开槽圆柱谐振器,计算出有孔圆柱介质谐振器的谐振频率。求解结果与矢量网络分析仪测量结果吻合,误差在千分之四以内。且该有限元法计算软件采用MATLAB编写,可方便地被调用于矢量网络分析仪的VEE测试软件中,较好解决有孔及变形圆柱介质谐振器的设计、测量和微调等问题,特别是矢量网络分析仪的快速自动测量中。     

计算多层介质中微带环谐振器谐振频率的频域方法

本文介绍计算多层介质微带环谐振器谐振频率的一种频域方法。它是基于电磁场理论中“反应原理”,由求解不同区域中满足边界条件的波动方程出发,通过傅立叶－汉克尔变换得到频域中的一个广义积分方程。根据该方程的数值结果,可获得各种模式下的谐振频率随第二层介质层厚度及介电常数的变化曲线。与变分法比较,一致性很好。这种微带环谐振器在微波热疗中有着广阔的应用前景,本文结果将对临床应用起到一定的指导意义。     

计算多介质层矩形微带天线谐振频率的解析方法

提出一种分析多介质层矩形微带天线的解析方法。首先导出了计算多介质层微带线的等效相对介电常数的显式计算公式，进而得到了多介质层矩形微带天线谐振频率的解析计算公式和一些数值结果。与精确的数值方法结果和实验值作了比较，它们吻合得很好。本方法运算简单，特别适合于ＣＡＤ应用。     

非均匀介质谐振器的谐振频率分析与FDTD方法

为了揭示非均匀介质谐振器的谐振频率与非均匀介质的特性之间的关系,首先基于Matlab编码,应用时域有限差分法(FDTD),对一个均匀介质的谐振器进行了模型分析和结果仿真,与实测结果对比,仿真结果显示了FDTD方法的有效性。然后建立一个具有横向平面分层式结构的非均匀介质谐振器模型,通过调节各层介质不同的厚度比例,发现可以用两种固定的介电常数相异的介质来获取所期望的谐振频率。这个分析和模拟结果有助于设计模型简单、尺寸规格相近但谐振频率各异的介质谐振器。     

用于折射率仪的高Q腔谐振频率跟踪系统

提出了一种用于折射率仪的采用方波调制的微波高Q腔谐振频率跟踪系统，分析了其工作原理。计算机仿真结果表明，系统跟踪速度快，稳定性好，无稳态误差；在小型微波折射率仪中的应用结果表明，作为系统输出的VCO频率对高Q腔谐振频率的跟踪灵敏度优于5×10-8f0（f0为高Q腔谐振频率）。     

某经纬仪方位谐振频率分析

谐振频率是光电经纬仪的一个重要指标,直接影响着经纬仪的动态特性和跟踪精度。工程上对光电经纬仪进行谐振频率估算时,一般采用霍尔兹法。但实际上由于光电经纬仪结构十分复杂,很难精确地计算其等效惯量与刚度,即使算出来其结果的误差也很大。本文针对某经纬仪的垂直轴系进行结构简化,建立了方位谐振频率分析的弹簧力学模型,通过有限元分析计算了在等效支承条件下的前几阶固有频率和振型图。计算结果与伺服系统正弦激振测试结果基本一致。     

Computation of resonant frequencies and quality factors of cavitiesby FDTD technique and Pade approximation

The finite-difference time domain (FDTD) technique and the Pade approximation with Baker's algorithm are used to calculate the mode frequencies and quality factors of cavities. Comparing with the fast Fourier transformation/Pade method, we find that the Pade approximation and the Baker's algorithm can obtain exact resonant frequencies and quality factors based on a much shorter time record of the FDTD output     

Asymmetric resonant cavities and their applications in optics and photonics: a review

Asymmetric resonant cavities (ARCs) with smoothly deformed boundaries are currently under intensive study because they possess distinct properties that conventional symmetric cavities cannot provide. On one hand, it has been demonstrated that ARCs allow for highly directional emission instead of the in-plane isotropic light output in symmetric whispering-gallery cavities, such as microdisks, microspheres, and microtoroids. On the other hand, ARCs behave like open billiard system and thus offer an excellent platform to test classical and quantum chaos. This article reviews the recent progresses and prospects for the experimental realization of ARCs, with applications toward highly directional microlasing, strongcoupling light-matter interaction, and highly sensitive biosensing.     

System level simulation of a micro resonant accelerometer with geometric nonlinear beams

Geometric nonlinear behaviors of micro resonators have attracted extensive attention of MEMS (microelectro-mechanical systems) researchers, and MEMS transducers utilizing these behaviors have been widely researched and used due to the advantages of essentially digital output.Currently, the design of transducers with nonlinear behaviors is mainly performed by numerical method and rarely by system level design method.In this paper, the geometric nonlinear beam structure was modeled and established as a reusable library component by system level modeling and simulation method MuPEN (multi port element network).A resonant accelerometer was constructed and simulated using this model together with MuPEN reusable library.The AC (alternating current) analysis results of MuPEN model agreed well with the results of architect model and the experiment results shown in the existing reference.Therefore, we are convinced that the beam component based on MuPEN method is valid, and MEMS system level design method and related libraries can effectively model and simulate transducers with geometric nonlinear behaviors if appropriate system level components are available.     

波浪式MEMS谐振陀螺的设计与研究

提出并研制了一种具有高机械灵敏度和低零偏稳定性的新型波浪式MEMS谐振陀螺(WDRG)。该结构的设计方法是将传统的环式MEMS谐振陀螺(DRG)转变为波浪式环,以提供更高的热弹性品质因数。此外,与传统DRG相比,WDRG具有更高的制造误差抗扰度。通过优化结构参数,进一步提高了WDRG的性能。通过有限元法(FEM)给出了主要结构参数对WDRG性能的影响。优化后WDRG的热弹性品质因数、机械灵敏度和偏置稳定性分别为450k,1.05μm/(°/s)和0.076(°)/h。与传统DRG相比,零偏稳定性降低了90%,热弹性品质因数和机械灵敏度分别提高了215%和950%。     

Precise computations of resonant frequencies and quality factorsfor dielectric resonators in MICs with tuning elements

In this paper, the highly accurate results of resonant frequencies, field distributions, and quality factors of the TE_01δ mode for the cylindrical shielded dielectric resonator (DR) in microwave integrated circuits (MIC's) with a practical tuning element, such as the metallic tuning screw and the dielectric tuning device, are presented. By using the newly developed FD-SIC method, numerical results can be calculated accurately and efficiently. The DR structures with tuning elements can be more easily modeled by the present approach than the other methods using approximate solutions or the mode-matching (MM) methods. Numerical results in the literature are compared to the present FD-SIC results for the DR without tuning elements and detailed discussions on these results are given. In addition, design curves are also presented for the DR with the metallic tuning screw and with the dielectric tuning device. These design curves are helpful for designing DR systems with tuning elements in MIC applications     

Bulk GaN-based SAW resonators with high quality factors for wireless temperature sensor

Surface acoustic wave (SAW) resonator with outstanding quality factors of 4829/6775 at the resonant/anti-resonant frequencies has been demonstrated on C-doped semi-insulating bulk GaN. The impact of device parameters including aspect ratio of length to width of resonators, number of interdigital transducers, and acoustic propagation direction on resonator performance have been studied. For the first time, we demonstrate wireless temperature sensing from 21.6 to 120 °C with a stable temperature coefficient of frequency of –24.3 ppm/°C on bulk GaN-based SAW resonators.     

等边三角形、正方形和平行四边形微光学谐振腔品质因子的比较

采用时域有限差分和 Padé近似计算了等边三角形、正方形和平行四边形微谐振腔的模式频率和品质因子 .数值结果表明等边三角形谐振腔中的谐振模式具有较高的品质因子 ,这主要是由于等边三角形谐振腔中的模式在横向上得到了完全的限制 ,而在其它两种谐振腔中 ,模式在横向上只是得到部分限制 .对于边长为 4μm,折射率为 3.2的等边三角形谐振腔 ,发现在 1.5 5 μm波长处的模式品质因子可达 5 .5e3.     

Co和Ca掺杂对(Mg0.7Zn0.3)TiO3系微波介质陶瓷性能的影响

采用固相反应法制备了(1-y)(Mgo.7Zn0.3)1-xCoxTiO3-yCaTiO3(MZCCT)(x=0～0.2,Y=0.03～0.09)微波介质陶瓷.研究了Co和Ca掺杂对所制陶瓷的相结构、烧结性能和介电性能的影响.Co掺杂后,MZCCT陶瓷的密度增大,Q·f值从90 000 GHz提高到152 000 GH...     

带负载匹配耦合谐振电路的能量与数据传输

为了提高耦合谐振电路中负载端的工作距离,使其达到30 cm 以上,并且能从负载端传输数据回发射端,基于频率分裂原理,设计了带负载匹配的能量与数据传输电路.对串联电路研究可知,满足一定传输功率的最大传输距离和负载阻值相关.而带负载匹配的串并混联电路在小幅降低传输功率的情况下可以通过调整等效负载电阻大小来增加传输距离.基于反向散射原理和混联电路的负载特性,可以在均衡传输效率和传输距离的情况下,选取合理的负载调制电路,实现数据从负载端到发射端的传输.matlab 仿真验证了以上结论,而系统实测表明,相比于串联电路,串并混联在保证数据正确传输的前提下,极限工作距离达到38 cm,提升20%以上.